A spring mass $$-$$ dashpot system is shown in the figure. The spring stiffness is $$K,$$ mas is $$m$$, and the viscous damping coefficient is $$c$$. The system is subjected to a force $$\,{F_0}\cos \omega t\,\,$$ as shown. Write the equations of motion which are needed to determine $$x.$$ (No need to determined $$x.$$)

The suspension system of a two-wheeler can be equated to a single spring-mass system with a viscous damper connected in series. Sketch the free body diagram and give the equations of motion. For a mass $$m = 50$$ $$kg$$ and a spring with a stiffness of $$35$$ $$kN/m,$$ determine what should be the damping coefficient (damping constant) for critical damping. What can be the damping force for a plunger velocity of $$0.05$$ $$m/s$$?

A cylinder of mass 1 kg and radius 1 m is connected by two identical springs at a height of $$0.5m$$ above the center as shown in the Fig. The cylinder rolls without slipping. If the spring constant is $$30$$ $$kN/m$$ for each spring, find the natural frequency of the system for small oscillations.